The objectives of this research are to design and construct a clinical version of a system for microwave thermokeratoplasty with surface cooling for correction of myopia, and to assess the refractive effects of such treatments in animal subjects after one year. Specifically, the applicants proposed to improve the system tested in Phase I of this project by adding features that reduce the technical skill required to treat. Furthermore, the proposed to test the hypothesis that two specified diameters of treated ring in the cornea would produce stable, specified changes in refraction after one year. Microwave thermokeratoplasty shrinks the stromal layer of the cornea in a ring around the optical zone through absorption of microwave energy in order to change the curvature of the cornea and hence its dioptric power. The proposed system incorporates surface cooling to protect the epithelium from elevated temperatures. Consequently, there is no need to wait for re-epithelialization after treatment, as is the case with current techniques, such as radial keratotomy and photorefractive keratectomy. There is significant commercial potential for this device, since roughly 50% of the U.S. population requires correction to vision. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE